Earth’s magnetic pole reverses

For about thirty years, the magnetic north pole has been moving faster and faster, leaving Canada towards Siberia. This abrupt change is still difficult to explain but could well be the beginning of a reversal of the magnetic poles. In any case, scientists must increasingly review the magnetic model of the Earth that serves as the basis for modern navigation systems.

Earth’s magnetic field has its origin in the slow cooling of the interior of our planet’s outer core where there is a superheated and swirling ocean of liquid iron which creates convection movements, between 2,900 km and 5,150 km below our feet. . Other factors are involved, such as the magnetized rocks in the earth’s crust and the flow of the oceans, in particular via the tides, whether on the surface or in the depths.

Convection movements in the outer core generate a dynamo effect called geodynamo, which converts a fraction of the energy released by cooling into electromagnetic energy.

This magnetic field forms the magnetosphere located between 800 to 1000 km altitude. It acts as a shield that protects life on Earth from excess solar wind.

First measured in 1831 by explorer James Clark Ross in the Canadian Arctic, the magnetic field is unstable on the scale of geological time. Indeed, one of its most astonishing characteristics, revealed by paleomagnetic studies, is the random reversal of the magnetic poles. In other words, magnetic north and south, which are located near true north and south, respectively, reverse at a chaotic rate with an average of about four events per million years, or once every 250,000 years. .

The consequences of a reversal of the magnetic field

The last magnetic field reversal occurred about 780,000 years ago. If these reversals have not, a priori, been accompanied by major biological crises, a new shift in the magnetic field would be a real challenge or even a catastrophe for our technology-dependent civilization. Indeed, the electronic, computer and navigation systems would be completely disrupted / disoriented and therefore the entire world economy and transport. Here are some consequences:

The magnetic north pole is moving faster and faster

In the mid-1990s, the magnetic north pole moved faster and faster, moving from about 15 kilometers to about 55 kilometers per year.

In 2001, an international polar expedition discovered that he had entered the Arctic Ocean and traveled around 300 km in just 7 years!

This phenomenon worsened further at the beginning of 2018. It is moving away quickly and more chaotically from Canada towards Siberia, without geologists being able to really determine why this change is so sudden and so spectacular.

Hypotheses are put forward: geomagnetic pulses, like the one in 2016, could be attributed to “hydromagnetic” waves coming from deep in the heart of our planet. And the rapid movement of the north magnetic pole could be linked to a high-speed jet of liquid iron beneath Canada.

And the magnetic south pole?

The magnetic south pole also moves, but more slowly than the north pole. It left the Antarctic continent in the 1970s and is moving northeast.

The movement of the magnetic poles is traced on our interactive cartography dedicated to the position of the magnetic poles.

The magnetic model of the Earth called into question

Regularly, specialists in geomagnetism or geomagnetists develop and revise the magnetic model of the Earth which serves as the basis for all modern navigation: control systems for ships at sea, airplanes, GPS for smartphones.

Thus, the model, updated in 2015, must already be reviewed as the movement is accelerating. “The error is constantly increasing,” said Arnaud Chulliat, geomagnetist at the University of Colorado Boulder and the United States Agency for Oceanic and Atmospheric Observation.

In 2016, for example, part of the magnetic field accelerated beneath northern South America and in the eastern Pacific Ocean. These geographical variations of the magnetic field are recorded every day by the Swarm satellite of the European Space Agency (ESA).

In 2018, the model’s margin of error became too large: the global magnetic model had to be updated before January 15, 2019, but the shutdown in the USA led to the closure of the American federal government, which was notably responsible for this task.

As soon as the political situation has stabilized in the USA, the update will be carried out before the one already planned for 2020. In the meantime, navigation errors are possible.